Answer:
y = 20x + 280
Step-by-step explanation:
The linear equation that represent your account balance is as follows:
Your friend
y = 25(6) + 250
= 400
And,
You
400 = m(6) + 280
6m = 400 - 280
6m = 120
m = 20
Now the equation of the account balance is
y = 20x + 280
Hence, the linear equation that represent your account balance is y = 20x + 280